Siliconera reports that the Japan version of Sonic Unleashed — titled Sonic World Adventure — will be delayed until Spring 2009. It was originally scheduled for a Dec. 18 release date. Sega is using the time to improve Sonic World Adventure, but Sonic Unleashed is still on target for its North American dates (PS2, Wii on Nov. 18, 360 on Nov. 24, PS3 on Dec. 12). The Wii version of Sonic World Adventure is not affected by the delay. It's a valid point — is Japan getting a noticeably different game, or will Sega USA follow suit and delay the title too? Sega Delaying PS3/360 Sonic Unleashed to Improve Quality, but Only in Japan [Siliconera]